Mortar and pestle



Sept. 20, 1932. E CHQTT 1,878,263

MORTAR AND PESTVIVJE Filed NOV. 13, 1929 Patented Sept; 20,1932 7 nnwAim L; (:HrirfI'orf'iaiCaGd Innnvois f This inventionrelates 1 t mo-rtars and pestles, and more particularly'to .devicesof this character- 'for preparing dentalamalgains and other characteristically similar 1 As is well known, dental amalganisusually comprise a triturated mixture of a characteri Ough mixing 'and "amalgamation thereof "are" "absolutely essential to secure the proper res 'sults, f The principal object of the present invention is to produce a' peculia'rly formed mortarand "cooperating pestle, more particularly' for use in the production of dental amalganis' and the like, but without limitation to such use, in whichprovisionis made for a full "and complete contacting' or tritu-rating surface andforfpreventing displacement of the mercury-or other ingredient up the side wall:

of the motar, wherebyto secure'abe'tter and quicker-result; to provide fo-rreadily ob-serving the conditionof the material ii'rthe course of trituration; and to attain certain other advantages as will be hereinafter more fully set forth.

- The invention consists in the novel construction and arrangement of the mortar and o pestle, and in their cooperative action, as

will be hereinafter fdescriloed and pointed particularity in the appended out with claims. I

In the accompanying drawing, forming a part of this specification, and illustrating a practical adaptation of the invention,

' Fig. 1 is a perspective view of the'mortar with the pestle supported therein; v V

Fig. 2 is a fragmentary detail view, onan enlarged scale, the mortar beingshown in vertical cross section, and the lower portion of the pestle inserted the-rein being shown in elevation, the handle-portion. ofth'e pestle is ahorizontal,,sectiointakeii on or aboutthe line 3,3 of-FigJQ. 1-

Referring now to the drawing,the nuiheral' :5designates generally the mortar and :6 the pestle; 1 rAs shown, the bottomcof themortar "is 'flatte'ned on its outer face, as at ,7 audits side wallsyaremupvwardly convergent on the :=outside,:as at- 8. ,The,;inner face 9fof the bottom of the mortar, is flattened and the upper portion 10 of-the inner faceofthe side 69 a lwallis truly cylindrical or perpendicularto said bottom face 9. In the lower portion of the inortaris provided an' annular groove 11, 7 T whichundercuts the-inner face lo ofthe' side wall and merges withthe inner face;9;of the :6

,bottomwall of the mortar, said annular groove being.,cross-curved, as at 1-2, on -a p j radiusequal to one-,half the diameter of a spherical head 13 provided atthe endwof the =reduced'neck portion 14 ofthepestlefia. I 7

' According to the; present inventioniand for the objects to be, attained-thereby,the groovell of the mortar and the spherical head 13 of the; pestle are correspondingly formed with accuracy, and for thepurposes 5 for which theinvention is more particularly intended, the mortar and pestle are T preferably .Jma-de :lof' a metal known. as strainless 1steel, but:thea same may be made of other suitable or approved non-corrosive material. 1 m Preferablyflthei handle portion :15 lot-the .pe'stle is fmade1 hollow, so that :it; may be fofsuflicieiitsize to beheld firmlyin-thefhand V but'x l-ight iniweight soas not'toibe-topheavy. a "Therhandleyportion l5 is alsopre ferably prof '..-vid'e'd*-:with 'd'iaine"trically opposite projections-1 6 which, asj'a conveniencein manufac- -tureomay be: a pin secured as by a; drive fit or otherwise inf diametrically alined apertures provided thereforin' the hollowed'portion= of.:.r;thelhandle,.saidpmjectionS lG ,pre-

venting the pestle from rolling arable -or other fiatsupporting'surface. w

' the.?use of the mortar} and pestleeithe present invention the mercury and alloyto :2 7' 5 comprise the amalgam, the -alloyiinnthe form -0fr filings'ror shavings and the" my, in a a V measuredidrop '01glebuleaiaieiipleedi f- .7 V v i being broken away and. shown partly in sec-,1 tion;and

mortar and subjectedto therollingandgpressalloy will fall together in the lowest part of the groove 11, and upon each rotation of the head 13 of the pestle in the groove it will work upon and through the entire mass. When the pestle is rotated the force is naturally exerted downward and outward, and as the circumference of the spherical head 13 is of a curvature corresponding to the transverse curvature of the annular groove 11, greater contact is afforded, thereby hastening the amalgamation of the mercury and alloy and resulting in an ideally smooth and plastic product which is obtained by mixing and forcing the mercury into the alloy'by a rolling pressure rather than by a grinding action. In mixing the amalgam in the groove 11, even when the mortar is tilted at a considerable angle, the annular shoulder 17 afforded by the undercutting of the groove 11 prevents the ingredients,

particularly the mercury which is more liable to do so, from working by displacement up the face 10 of the mortar.

- By the provision of the characteristic undercut groove 11 in the mortar and the cooperating spherical head 13 of the pestle, not only is the amalgam produced ideally and with comparative rapidity, but also the condition of the product is readily observable as the treatment progresses, which is of considerable advantage, for care must be exercised so as not to over or under mix the ingredients.

By having the handle portion 15 of the pestle hollow, as hereinbeforedescribed, the handle may be made sufficiently large to provide for a firm grasp in manipulating the pestle, and at the same'time the preponderance of the Weight will be in the neck portion 14 and spherical head 13 within the mortar, so that the liability of accidentally-tipping over the mortar is greatly minimized and by which arrangement the mortar with the pestle therein has a tendency to right itself from the tilted position should the operator release his hold thereon in the course of pr-eparing the amalgam or other admixture in the mortar; As shown, the mortar is provided with a circumferential annular groove 18 near its bottom which enable the operator to secure a firm grasp upon the mortar whereby to hold it either in flatwise or tilted position.

construction and arrangement shown in the accompanying drawing.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination of a mortar whose working cavity has a flattened bottom, a cylindrical upper wall portion, and an annular groove in its wall transversely curved and merging tangentially with said flattened bottom without interruptive protuberance and providing an annular undercut interruptive shoulder where said groove merges with the upper side wall portion of the mortar, and a pestle having a spherical head portion, said head portion being cooperative with the annular groove in said mortar, and said annular groovebeing transversely curved corresponding exactly to the circumferential curvature of said spherical head.

2. A mortar having a flat relatively thick bottom wall'and an upwardly tapering annular sidewall, the cavity of said mortar being grooved annularly coincident with the corner of its bottom and side walls, the groove being uniformly rounded transversely at every point, and the base portion of the mortar having an external annular groove therein.

3. A mortar having a flat relatively thick bottom wall and an upwardly tapering annular side wall, the cavity ofsaid mortar being grooved annularly coincident with the corner of its bottom and side walls, the groove being curved on the same radius transversely and merging at its lower side tangentially with the bottom face of the cavity without interruptive protuberance at any point, the upper side of said groove merging at every point with the face of the side wall of the cavity in an undercut shoulder, the base portion of the mortar being provided with an external annular groove, a I

In testimony whereof I have signed my name to thisspecification, r o

r EDWARD L. OHOTT.

Obviously, the device admits of consider- I able modification without in the least departing from the spirit and scopeof the invention asdefined by the appended claims. The invention, therefore, is not limited to the specific 

